Olaf,
unfortunately the activate provided by squiggle/batik is merely a
pseudonym for click,
according to my test it responds to click but not enter
iirc cameron has for some time been concerned with the lack of
keyboard navigation.
however your response regarding the failure of other UAs to provide
functionality does not prevent you proposing a single suitable
solution with testcase,
for a variety of different input devices.
And it might be hoped that such a discussion might better enable
implementation.
It may even be necessary to raise an errata, as the gross failure to
implement may at least be suggestive.
cheers
Jonathan